Hot barrels and wandering zero?

Outstanding in my field

Well-Known Member
Relatively new centrefire rifle shooter. I've got a Bergara hunter, but I'm trying to get practice with it. Have been on a 100m range and although the first few shots will be where I'd expect soon after the POI starts wandering. It will still give a 4"group but POI is random and that's not the sort of accuracy I'm after! Also it makes testing ammo to find preferred round impossible.

I want the confidence that the bullet is going where I want it and that means practice and range time. Should I go for a Varmint barrel with the associated extra weight (I need to lose a few pounds anyway) or I've read that cut barrels e.g. Schultz & Larsen don't wander so much when they heat up. Heavier barrel or cut barrel?

Thanks
 

andyk

Well-Known Member
I suggest not getting your barrel hot enough for this to be a problem. Any barrel will wander when hot enough, the benefit to heavier barrels is it take more shots to heat them up (conversely, they take longer to cool). There may also be a slight benefit to increased rigidity, but you can't deny science which says as the metal heats, it will expand.

If your barrel is getting hot enough to cause that much of a POI shift you will be seriously shortening your barrel life as barrels wear faster when hot than when cold. My own approach is never to let a barrel get too hot to touch unless there is a good reason to do so, ammo testing is not a good reason.

If the rifle is purely a target rifle, then yes a heavy barrel is a good option. Otherwise, I'd just give it a minute or so between shots.
 

Woodsmoke

Well-Known Member
Yep, as above. I have Sporter barrels on my rifles, and limit my shooting to three rounds at a time to check grouping. Then the rifle gets left alone to let the barrel cool, even though it's not hot enough to make you let go if put your hand on it
 

Erik Hamburger

Well-Known Member
Having had the same kind of trouble with a Howa 1500 Sporter, some 10 years ago, bad groups, stringing, etc. I naturally blamed my rifle. However a session at a local Range, under a good Instructor (Paul Hill at the Corinium Range) soon showed the issues were with my hold and body position. I am still using that same rifle, the same moderator, and factory loaded bullets to good effect now.
 

Foxyboy43

Well-Known Member
Hmm. From what you say and if you are only after live quarry you will not need (hopefully) 3-4 shots so your “wandering” will not be an issue.
Not sure of chambering but if it is large then after only a few shots “flinch” can appear which can give you precisely what you are experiencing especially if not moderated, so yes to all above but fundamentally first off make absolutely sure you have a constant stable position on a solid table with bags fore and aft, then concentrate on your hold, breathing and trigger release.
This is also a much cheaper way of possibly solving your issue!
🦊🦊
 

Rewulf

Well-Known Member
It will still give a 4"group

4 inch group at 100 m !
Id be checking barrel stock clearance , scope and mounts tight ect.
Wandering to me is an inch or so , from a 1 inch or better group at 100, and could easily be countered by letting it cool between shots, but that sounds like something else entirely.
You cannot shoot a centrefire like a rimfire, the barrel wont stand for it , and could be worn out VERY quickly if you do, but 10 , even 20 rounds in 10 minutes isnt terrible .

A 4 inch group would be unacceptable to me.
 

Utectok

Well-Known Member
I have a fluted lightweight barrel 5 shot strings and no wandering poa. Then I’ll usually wander up to the target and bugger about a bit before next go. If you are a beginner it’s very hard to say what is causing the group’s. I suspect as many have pointed out a big factor could be you? Get someone else to have a go? Obviously if your shooting 20-30 shots in quick succession this may not be advisable. Take your time trying to keep shot rate below 1 a min even with 5 shot strings. My experience is shooter failure is the first problem most of the time then something lose usually scope mounts ect then occasionally it’s the gun……. forend touching barrels or something. Good luck enjoy
 

Alantoo

Well-Known Member
Get an experienced shot to shoot your rifle and that will instantly tell you if it is a problem with the gun and ammo or the shooter.

It is what I did, and it proved to be a problem with the shooter in my case.

The good thing is that problems with the shooter are only fixable by the pleasurable activity of more trigger time.

If it turns out to be a problem with loose mountings or a duff scope you don't get to have the same excuse justification imperative need for practice!

Alan
 

Edinburgh Rifles

Well-Known Member
Sorry, any barrel that wanders after 5 shots is not a rifle, its an expensive tomato stake
I ran a 300wm sporter barrel and regularly shot strings of 15-20 rounds until I could cook bacon on it!
no POI shift

I have a Sporter barrel 300 Norma Mag with a 16mm muzzle on a 24" tube
I push 85gr of powder through it

POI shift on skinny barrels is as much a function a change in the physical interference on the stock as things heat up.
either in the barrel channel or ropey fixing in the action/body of the stock.

That said Bergara rifles are very accurate and 4" is not a group I would expect from a new one
Investigate
Get someone else to shoot it to exclude you
try some Geco Ammo. they test some of their rifles with it and they usually have a target in the box is significantly MOA.
like 1/4-1/2"
 
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Outstanding in my field

Well-Known Member
Sorry, any barrel that wanders after 5 shots is not a rifle, its an expensive tomato stake
I ran a 300wm sporter barrel and regularly shot strings of 15-20 rounds until I could cook bacon on it!
no POI shift

I have a Sporter barrel 300 Norma Mag with a 16mm muzzle on a 24" tube
I push 85gr of powder through it

POI shift on skinny barrels is as much a function a change in the physical interference on the stock as things heat up.
either in the barrel channel or ropey fixing in the action/body of the stock.

That said Bergara rifles are very accurate and 4" is not a group I would expect from a new one
Investigate
Get someone else to shoot it to exclude you
try some Geco Ammo. they test some of their rifles with it and they usually have a target in the box is significantly MOA.
like 1/4-1/2"
Thanks. All helpful advice. I should have said it's a second hand rifle "barely shot by its previous owner" according to the gun shop. Hmm.
 

Utectok

Well-Known Member
In which case ,I would beg ,borrow or buy a borescope and have a look, if it turns out to be not as described......
Borescopes don’t tell you massive amount unless you have looked down a few barrels to the inexperienced it usually just looks horrible.
 

Rewulf

Well-Known Member
Borescopes don’t tell you massive amount unless you have looked down a few barrels to the inexperienced it usually just looks horrible.
I know what you mean , but if there is obvious indicators like missing throat rifling , or a damaged crown area ?
I had a gunsmith cut and recrown my .223 barrel recently , somehow he damaged the last quarter inch of rifling, result , 8-9 inch groups !
Another cut sorted it , but without my trusty £50 borescope , I would never have seen the problem.
 

HappyHunter

Well-Known Member
That is some shift! I'm running a Howa Alpine (pencil thin barrel) in .308.

Mostly restricted to 3 shot strings then a break, but in the early days I did throw some lead!

Still, any shift in poi was negligible.

It appears something is 'wrong', but don't panic. Lots to try and likely something simple.

- mod coming loose (mine does this)
- prolonged shot strings
- Bedding of action / stock clearances
- Flinching

To name but a few.

HH
 

NullMac

Well-Known Member
Gee, how are you meant to make sense of all that. You didn't say calibre. You didn't say how many rounds were good and it wandered off.

Still 4" is huge. Even "fliers" are not that bad.

No point changing the barrel as you don't know that's the problem.

If you are new to this game then suspect yourself first :

- EITHER Get a mate who you know can shoot to put a couple ie two, shots through it. Wait a bit do it again. No need to "group" it, you just want to prove that it is not spraying things around or otherwise. Don't shoot heaps of ammo, it either works or it does not.

- OR Any accuracy testing should have the shooter removed. So if you don't have "sniper" for a mate, big sandbag at the front, big sandbag at the back, get a super stable positions and apply the minimum amount of contact from you to get consistent recoil management.

I assume you have tried a couple of types of ammo.

If it is still crap then - Check scope mounts -Change the scope out and Retest.

After that you can be confident that the rifle is at fault.

The next step is to take it to a gunsmith unless you have a torque wrench. If you do it would be worth separating the action from the stock and checking the contact points for crap, high points, oil, whatever then tightening to the correct torque.

After that its defo the 'smith.

I have a Bergara and it shoots as well as and probably better than any rifle I have owned except my AI. You don't need a varmint barrel to shoot accurately.
 

Sash

Well-Known Member
Sorry, any barrel that wanders after 5 shots is not a rifle, its an expensive tomato stake
I ran a 300wm sporter barrel and regularly shot strings of 15-20 rounds until I could cook bacon on it!
no POI shift
I used to believe/accept that sporter barrels, in particular, would "string" vertically as they got hot, and become unacceptably innaccurate after a few rounds.

But my more recent experience of (vaguely) competitive shooting with a .308 Tikka T3 Hunter has reduced my concerns, and would tend to suggest that you might have a different problem with your setup. Especially since you describe the POI as random.

My most recent example was shooting the Sporting Rifle competitions at the NRA Imperial Meeting last weekend: I fired the Running Deer and Swedish Deer competitions back to back (24 shots in all) and, as Ed describes, both barrel and mod were extremely hot to touch on completion. But there was absolutely no evidence in the scoring/POIs of any sort of vertical "stringing".
 
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